https://www.youtube.com/watch?v=W_x8DiMa7xA&feature=em-uploademail
Some nice stuff there. Really highlights the difference between the Fairley and the Garrett. The Fairleys (the first loco seen in the video) are essentially two complete locomotives joined back-to-back. The Garretts are two engines under one boiler, akin to more conventional articulateds. I rode the Festiniog some 30 years ago. IIRC, the motive power was a 2-6-2 former trench engine. Still think Bachmann should seriously consider doing a Garrett in On30.